JAVA中使用Google Guava的CacheBuilder类写一个定时缓存

关于CacheBuilder

CacheBuilder是Guava用于创建LoadingCache、Cache实例的构建类

导入Maven依赖


   com.google.guava
   guava
   27.0.1-jre


代码实现

/**
 * @author chuan
 * @title: CacheVo
 * @description: TODO(缓存字典)
 * @date 2019/7/16 15:12
 */
public class CacheVo {

    private final LoadingCache>  cache_code_name;
    /**
     * 缓存赋值
     * expireAfterWrite是在指定项在一定时间内没有创建/覆盖时，会移除该key，下次取的时候从loading中取
     * expireAfterAccess是指定项在一定时间内没有读写，会移除该key，下次取的时候从loading中取
     * refreshAfterWrite是在指定时间内没有被创建/覆盖，则指定时间过后，再次访问时，会去刷新该缓存，在新值没有到来之前，始终返回旧值
     * duration  持续时间
     */
    public CacheVo(){
        cache_code_name= CacheBuilder.newBuilder().expireAfterWrite(10, TimeUnit.SECONDS)
                .build(new CacheLoader>() {
            @Override
            public Map load(String s) throws Exception {
                Map> strMap = Maps.newHashMap();
                Map item1 = Maps.newHashMap();
                item1.put("1001","ACODE10001");
                item1.put("1002","ACODE10002");
                item1.put("1003","ACODE10003");
                item1.put("1004","ACODE10004");
                strMap.put("item1",item1);
                Map item2 = Maps.newHashMap();
                item2.put("1001","BCODE10001");
                item2.put("1002","BCODE10002");
                item2.put("1003","BCODE10003");
                item2.put("1004","BCODE10004");
                strMap.put("item2",item2);
                System.out.println("------------缓存更新完成-----------");
                return strMap.get(s);
            }
        });
    }

    /**
     * 获取MAP
     * @param code
     * @return
     * @throws ExecutionException
     */
    public Map name(String code) throws ExecutionException{
        Map strMap = cache_code_name.get(code);
        return strMap;
    }
    // 执行
    public static void main(String[] args) throws Exception{
        CacheVo vo = new CacheVo();
        List ls = Lists.newArrayList();
        ls.add("item1");
        ls.add("item2");
        for (int i = 0; i < 100; i++) {
            int v = (int) (Math.random() * 2);
            int itemNumber = (int) (Math.random() * 4)+1;
            Map name = vo.name(ls.get(v));
            System.out.println(ls.get(v) + "---------->"+name.get("100"+itemNumber));
            TimeUnit.SECONDS.sleep(1);
        }
    }


}